The only known living species of Congeria, a dreissinid genus formerly
widespread in Central European lakes and seas (now largely gone too), is
also the only freshwater cave-dwelling bivalve I know of.  It is from
Yugoslavia (not sure what country now, as I do not have the paper handy)
and is not known outside of caves.

Several marine species are found primarily or exclusively in caves,
although these are often cryptic and sometimes quite small.  Some also
represent typically deep-water genera or families.  All of these factors
would make it likely that they could occur elsewhere but have been
overlooked.

Do boring or burrowing taxa count as constructing their own miniature
caves?  What about nestlers, occupying existing crevices?


Dr. David Campbell

"Old Seashells"

Department of Geological Sciences
CB 3315 Mitchell Hall
University of North Carolina at Chapel Hill
Chapel Hill NC 27599-3315
USA

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919-962-0685
FAX 919-966-4519

"He had discovered an unknown bivalve, forming a new genus"-E. A. Poe, The
Gold Bug